1. Field of Invention
A pressurized syringe used to inject a viscous liquid through an adapter attached to a bone filler adapter into a cannulated surgical screw utilizing the cannulated surgical screw as a port to inject bone void filler into a bone void within a bone cavity during the course of a surgical repair to attach, repair and secure broken or separated bone fragments and providing a more secure bone anchor matrix within which the surgical screw is set.
2. Description of Prior Art
A preliminary review of prior art patents was conducted by the applicant which reveal no prior art patents in a similar field or having similar use in the field of orthopedic surgery. The disclosed prior art inventions do not disclose the same or similar elements as the present pressurized syringe attaching to a cannulated screw bone filler adapter, nor do they present the material components in a manner contemplated or anticipated in the prior art.
Bone cements are known in the art of orthopedic surgery and have been discussed in articles including The use of Calcium Phosphate Bone Cement in fracture Treatment, Bajammal, Sohail S., et al., Journal of Bone and Joint Surgery, Volume 90, pgs. 1186-1196, and articles referenced therein and in U.S. Patent Application No. 2007/0032567 to Beyar. Methods of injection of a bone filler are disclosed in U.S. Patent Application No. 2009/0054934, to Beyar, which provide methods for accessing a void in the bone, introduction of bone cement into a void, introduction of an expandable filler into the void, expanding the filler and allowing the cement to set. This application clearly points out a danger in contamination of non-intentional tissue surrounding the fracture site with the bone cement by leakage or by overfill causing further damage to the affected bone being repaired and also by introduction of the bone cement through mistake or accident. Other methods employing the use of a surgical procedure known as Kyphoplasty, wherein a balloon is inflated within a bone void with the balloon further filled with a bone filler material to minimize collateral exposure to the bone cement, is demonstrated in U.S. Patent Application No. 2006/0122625 to Truckai.
Another patent application, U.S. patent Application No 2007/0055257 to Vaccaro, has attempted to utilize modified cannulated screws to accomplish an injection of a syringe containing a bone filler, the head of the cannulated screw having an externally threaded inner head adapted to a syringe having an internally threaded collar with an injector tip which enters the longitudinal central bore in the cannulated screw, the cannulated screw having a side discharge port to release the bone filler injected into the central bore.
The present adapter and pressurized syringe utilizes a typical prior art cannulated surgical screw as shown in FIGS. 1A-1C, available from surgical supply companies including MIKROMED, DEPUY®, OSTEOMED® and SYNTHES®. The adapted secures to the head of the cannulated screw by screwing the two threaded components together, locking the adapter to the head of the cannulated screw. A pressurized syringe containing a viscous liquid, in the present case a bone cement, attaches to the adapter, dispenses the viscous liquid through an outer threaded end into an internally threaded head cap of the upper component of the adapter, after which the viscous liquid or bone cement contained within pressurized syringe is injected through the adapter and the longitudinal central bore of the cannulated screw through the tip of the cannulated screw into a bone void below the tip of the cannulated screw which will secure the tip of the cannulated screw into the bone void filler cement subsequent to the hardening of the cement. Anchoring the tip of the surgical screw would reduce the chance of the screw backing out of the bone, which is not an uncommon occurrence, in the same manner that filling a post hole with cement to anchor a fencepost stabilizes and supports the fencepost over simply ramming the fencepost into the dirt.
Several syringes are disclosed in the prior art which appear to apply a greater force than a common syringe employing a plunger and a cylinder. Prior art devices include a bone cement syringe which provides a syringe within a syringe, the inner syringe filled with paste, and the outer syringe holding the inner syringe with the outer syringe having a threaded plunger system, as indicated in U.S. Patent Application Publication 2004/0030345 to Aurin. A bone cement mixer and dispensing syringe is also disclosed in U.S. Pat. No. 4,277,184 to Solomon. A syringe device for injecting bone cement into a cannula, or hollow tube inserted into a bone, is disclosed in U.S. Patent Publication No. 2007/0185496 to Beckman.
Syringes having a threaded plunger in relation to the syringe body include U.S. Pat. No. 2,283,915 to Cole and U.S. Pat. No. 3,353,718 to McLay. Portions of syringes provide prior art references including U.S. Pat. No. 7,604,618 to Dixon, disclosing a high pressure injection syringe having an expanded and reinforced plunger tip having an O-ring sealer used with a screw engaged plunger with a great emphasis involved in the disclosure of the viscoselective seal involved in the tip of the plunger. Another viscous fluid syringe, disclosed in U.S. Pat. No. 6,997,904 to Sculati, provides a locking head assembly for retaining the syringe in the cylindrical syringe sleeve which includes a top plate and a locking flange which engages with the flange for locking the head assembly to the cylinder. The plunger in the syringe is discarded and when the locking head assembly is placed on the cylindrical syringe sleeve an internal flange with a gasket located on it is inserted into the top of the syringe chamber forming a seal. Other high pressure syringes are indicated in U.S. Pat. Nos. 7,041,084 to Fojtik, 5,540,657 to Kurjan and 5,078,690 to Ryan.
However, none of the prior art devices, together or individually, disclose the pressurized syringe which is used in conjunction with the bone filler adapter and a cannulated screw forming a complete and secure seal for the injection of a bone cement or other viscous liquid.